The present invention is related to Japanese patent application No. Hei. 11-355746, filed Dec. 15, 1999; 2000-229892, filed Jul. 28, 2000, the contents of which are incorporated herein by reference.
The present invention generally relates to an accelerator device, and more particularly, to an accelerator device in which both the axis of rotation of an accelerator member and the axis of rotation of an accelerator opening sensor rotate about the same axis.
Previously, an accelerator device equipped with an accelerator opening sensor was disclosed in Japanese published unexamined patent applications Heisei 10-287147 and Heisei. 11-59220. An accelerator device is used by a driver to control the engine by means of a accelerator pedal depressed by the driver""s foot or the like.
The accelerator opening sensor detects the amount of force applied to the accelerator pedal, i.e., the accelerator pedal""s angle of rotation or, in other words, the degree of accelerator opening. The degree of accelerator opening is used as control information and the like by the throttle device. The sensor disclosed in Japanese published unexamined utility model application Showa 62-97909 can be used as an accelerator opening sensor. Here, a contact member on the sensor rotor of an accelerator opening sensor contacts with a substrate coated with a resistor. When the angle of rotation of the sensor rotor changes by actuation of the accelerator, the position of the contact member and the resistor changes, and the value of the voltage output changes. The degree of accelerator opening can be detected by this change in voltage output.
In the accelerator device disclosed in Japanese published unexamined patent applications Heisei 10-287147 and Heisei 11-59220, the axis of rotation of the accelerator member having the accelerator pedal, and the axis of rotation of the sensor rotor of the accelerator opening sensor, are different. There are two axes. The level of pressing or accelerator actuation on the accelerator member is transmitted to the sensor rotor by means of the transmission member, and the amount of accelerator actuation is detected by the position of the rotation angle.
However, because there are different axes of rotation for the accelerator member and the sensor rotor, the axes of rotation must be aligned, and thus the number of parts increases. Consequently, the level of production complexity increases, and manufacturing costs climb. In addition, because there are two axes, the device becomes much larger. Furthermore, because the rotational movement of the acceleration member is transmitted to the axis of rotation of a different sensor rotor by means of a transmission member, the rate of change of the level of accelerator actuation and the rate of change of the sensor rotor are not the same, and errors are generated. Furthermore, if the position of the two axes accidentally shifts or deviates by warping in materials when the accelerator device is connected to an automobile chassis or the like, the degree of accelerator opening cannot be detected with a high degree of accuracy.
In order to eliminate these types of problems, rotating the accelerator member and the sensor rotor about the same axis of rotation has been considered. However, in an acceleration device in which these elements are rotated about the same axis, when the accelerator member slides due to a movement of the accelerator in other than a rotational direction, this shift or deviation is also created in the sensor rotor. When the sensor rotor slides, there is a danger that there will be poor contact between the contact member and a resistor and slide/contact type of sensor. Even with other types of sensor methods, there is the danger that a high degree of accuracy cannot be obtained there is shift or deviation in the sensor rotor.
The present invention provides a small accelerator device that detects the degree of accelerator opening with a high degree of accuracy. The present invention also provides an accelerator device that prevents the degree of accelerator opening from being fixed in the full open position, even if the recess portion and the protruding member inserted therein are damaged. In the present invention, both the accelerator rotor and sensor rotor rotate about a single support shaft that serves as an axis of rotation. Because one shaft serves as the axis of rotation, the accelerator device can be made small. In addition, compared to where the accelerator rotor and sensor rotor have different axes of rotation, alignment during assembly is easy. In addition, because the number of parts is reduced and assembly becomes easy, production costs are reduced. In addition, because the amount of actuation is transmitted from the accelerator rotor directly to the sensor rotor and not through a transmission member, the rate of change in the amount of accelerator actuation and the rate of change in the sensor rotor are consistent with one another. Thus, there are no transmission errors generated in the amount of accelerator actuation, and the degree of accelerator opening can be detected with a high degree of accuracy.
Furthermore, the support shaft does not rotate but is fixed to the support member, and the amount of accelerator actuation is transmitted to the sensor rotor due to the fact that the accelerator rotor and the sensor rotor are engaged with each other. Even if the accelerator rotor slides in a direction other than toward rotation due to accelerator actuation, the engaged configuration absorbs shift or deviation in the accelerator rotor, and thus the shift or deviation in the accelerator rotor is prevented from being transmitted to the sensor rotor, and the degree of accelerator opening can be detected with a high degree of accuracy.
The force applied to the sensor rotor in directions other than the direction of rotation by accelerator actuation can be broken down into the rotational direction, the support shaft direction, and the radial direction of the accelerator rotor.
In the accelerator device according to another aspect of the present invention, the accelerator rotor is prevented from shifting or deviating in the rotational direction with respect to the sensor rotor, and is engaged with the sensor rotor such that it slides in contact with it in the support shaft direction and in the radial direction of the accelerator rotor. When force is applied to the sensor rotor in a direction other than the rotational direction, even though the accelerator rotor slides in contact with the sensor rotor and the position shifts or deviates, the shift or deviation in the position of the accelerator rotor is not transmitted to the sensor rotor. Thus, the degree of accelerator opening can be detected with a high degree of accuracy.
However, it is difficult to both prevent the accelerator rotor from shifting or deviating in the direction of rotation with respect to the sensor rotor, and manufacture an engagement portion for the accelerator rotor and the sensor rotor such that the accelerator rotor and the sensor rotor slide in contact with each other in the support shaft direction and the radial direction of the accelerator rotor. In another aspect of the present invention, a plate spring is inserted into a recess portion formed in either the accelerator rotor or the sensor rotor, and a protruding portion formed in the accelerator rotor or sensor rotor not having the recess portion is engaged in the recess portion such that biasing force is received from the plate spring in the direction of rotation. Because the plate spring absorbs manufacturing errors, a high degree of manufacturing accuracy in the recess portion and the protruding portion is not necessary, and manufacturing becomes easy.
In another aspect of the present invention, more than 1 recess portion is formed in either the accelerator rotor or the sensor rotor, a plurality of protrusion portions are formed in the accelerator rotor or sensor rotor that do not have the recess portions and are engaged with the recess portions, at least one of the protruding portions receive biasing force in the rotational direction from a plate spring inserted into at least one of the recess portions and engaged with the recess portion. Even if a number of protruding portions are damaged, if at least one of the protruding portions remains undamaged, the engagement between the protruding portion and the recess portion can be maintained. Thus, the sensor rotor can be prevented from being suspended in the full open position.
In another aspect of the present invention, protruding portions are formed in the sensor rotor, and recess portions are formed in the accelerator rotor. Either at least one of the protruding members receives biasing force in the rotational direction from a plate spring inserted into the aforementioned recess portions, or at least one of the protruding members cannot move in the rotational direction in the engaged state with the recess portions that do not have a plate spring inserted therein, or if xcex81 is defined as the rotational angle of the gap formed in the rotational direction between a protruding member and the accelerator closed end surface of the recess portion, xcex82 is defined as the range of the angle of the rotational movement of the accelerator rotor, and xcex83 is defined as the rotational angle between the protruding portion and the accelerator open end surface of the recess portions that do not have a plate spring inserted therein, xcex81 is greater than xcex82 and xcex82 is greater than xcex83. Even if the protruding portion biased in the direction of rotation by the plate spring is damaged, because xcex82 is greater than xcex83, even if the sensor rotor is in the fully open position, when the accelerator rotor returns to the fully closed position, the protruding portion not biased in the direction of rotation by the plate spring will be engaged by the accelerator open end surface, and the sensor rotor will rotate to the closed position from the fully open position.
In addition, because xcex81 is greater than xcex82, when the accelerator rotor returns to the fully closed position, the accelerator closed end surface of the recess portion and the protruding portion do not contact. Because the sensor rotor stops in a closed position from a fully open position, and in this closed position the accelerator opening sensor can fix the detected degree of accelerator opening, the degree of accelerator opening can prevent fixing in the fully open position. The accelerator opening sensor approaches the closed state due to the small size of xcex83.
In another aspect of the present invention, a protruding portion is formed on the sensor rotor, a recess portion is formed on the accelerator rotor, and xcex81 is greater than xcex82, and xcex82 is greater than xcex83. Even if the protruding portion receiving biasing force from a plate spring in the direction of rotation is damaged, because xcex82 is greater than xcex83, even if the sensor rotor is in the fully open position, if the accelerator rotor returns to the fully closed position, the sensor rotor will rotate from the fully open position to the closed state. In addition, because xcex81 is greater than xcex82, when the accelerator rotor rotates from the fully closed position to the open state, the sensor rotor will rotate to the open position without reaching the range of the fully open position. In other words, while protecting against the degree of accelerator opening from reaching the fully open position, the degree of opening can be regulated by that range of degrees. The smallest degree of opening approaches the fully closed position due to the small size of xcex83.
In another aspect of the present invention, protruding portions are formed on the accelerator rotor, and recess portions are formed in the sensor rotor. Either at least one of the protruding members receive biasing force in the rotational direction from a plate spring inserted into the recess portions, or at least one of said protruding members cannot move in the rotational direction in the engaged state with said recess portions that do not have a plate spring inserted therein. Or if xcex81 is defined as the rotational angle of the gap formed in the rotational direction between said protruding member and the accelerator open end surface of the recess portion, xcex82 is defined as the range of the angle of the rotational movement of said accelerator rotor, and xcex83 is defined as the rotational angle between said protruding portion and the accelerator closed end surface of said recess portions that do not cave a plate spring inserted therein, then xcex81 is less than xcex82 and xcex82 is greater than xcex83.
In another aspect of the invention, a protruding portion is formed on the accelerator rotor, a recess portion is formed in the sensor rotor, and xcex81 is less than xcex82, and xcex82 is greater than xcex83.
In another aspect of the present invention, protruding portions are formed on the accelerator rotor, and recess portions are formed in the sensor rotor. Either at least one of the protruding members receive biasing force in the rotational direction from a plate spring inserted into the recess portions, or at least one of said protruding members cannot move in the rotational direction in the engaged state with said recess portions that do not have a plate spring inserted therein. Or if Theta 1 is defined as the rotational angle of the gap formed in the rotational direction between said protruding member and the accelerator open end surface of the recess portion, Theta 2 is defined as the range of the angle of the rotational movement of said accelerator rotor, and Theta 3 is defined as the rotational angle between said protruding portion and the accelerator closed end surface of said recess portions that do not have a plate spring inserted therein, then Theta 1 is less than Theta 2 and Theta 2 is greater than Theta 3.
In an accelerator device according to claim 8 of the present invention, a protruding portion is formed on the accelerator rotor, a recess portion is formed in the sensor rotor, and Theta 1 is less than Theta 2, and Theta 2 is greater than Theta 3.
In another aspect of the present invention, a tubular member is attached to the outer circumference of one support shaft non-rotationally fixed to a support member, and the tubular member is attached to an accelerator rotor and can rotate. A sensor rotor is attached to the support shaft and can rotate, and rotates together with the accelerator rotor. Because a sliding clearance is formed between the accelerator rotor and the tubular member, there is a danger of central axis shift or deviation in the accelerator rotor with respect to the tubular member. However, there is a cone-shaped concave surface in either the tubular member or the accelerator rotor, and a cone-shaped or pyramid-shaped convex surface formed in the tubular member or the accelerator rotor not having the cone-shaped concave surface. The cone-shaped or pyramid-shaped convex surface has a taper angle approximately the same as that of the cone-shaped concave surface, and in contact with each other in the support shaft direction. Then, because accelerator rotor is biased such that the central axis biasing means brings the cone-shaped concave surface and either the pyramid-shaped convex surface or the cone-shaped convex surface in contact with each other, the accelerator rotor receives centripetal force. Thus, shift or deviation in the central axis of the accelerator rotor is prevented.
In another aspect of the present invention, due to biasing of the sensor rotor in one direction of the support shaft, even though the accelerator rotor slides in the support shaft direction and the accelerator rotor and the sensor rotor slide in contact with each other, sensor rotor sliding due to sliding resistance in the support shaft direction is prevented.
In another aspect of the present invention, a sensor rotor is supported by a tapered surface formed in a support shaft, and the sensor rotor is prevented from movement in the support shaft direction and the orthogonal direction.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.